Captive dispensing and metering cap

ABSTRACT

A dispensing and metering cap construction comprising a threaded tubular spoutlike cap body and an orifice-type screw cap both of molded plastic composition. In addition to the screw threads on the cap and cap body, the cap has a stop lug which is especially arranged to constitute a cam follower whereby it also serves somewhat like a thread element adapted to engage a cam track at the base of the cap body. Both the screw threads and the cam track and follower lug serve to raise the cap on the cap body in response to unscrewing movement. The extent of unscrewing determines the size of the opening of the discharge orifice in the cap. The cam track constitutes a positive or nonyielding lead means for the cap, whereas the screw threads are yieldable and impositive. Thus the cam track is the dominating one of the two lead means. By providing a hump or depression in the cam track, an accurate raised axial position of the cap can be readily effected for a given rotative position, without requiring an accurate corresponding relative positioning of the screw threads, since the latter can be made to yield a lesser or a greater amount under the influence of the cam track. The provision of the hump or depression thus can be used to attain an accurate metering position of the cap, and is easier to accomplish than accurate reorientation of the screw threads.

United States Patent [72l Inventor Merton I. Stall e/o Stall EagravingCe. 2l32 81st Gull. Marathon. Ila. 33050 [2|] Appl No. 876334 l22l FiledNov. 14.1969 [45] Patented Aug. 16.19"

[54] CAI'IIVI DISPENSING AND METERING CAP 1 Clalras. QDrawlagIlgs.

I52] U.S.Cl. 222/48, 222/521 [SI] Iat.Cl..... W 561d 5/22 [50] Museums.222/499. 519, S20. $25. $62. 548. 449. S52. 55 l 550. $67. 56!. $72.S28. 529. 530. 52 l $09. $45.41. 44, 46-48; 2l5/40'. 15 N22 [56]lelersaeescltsd UNITED STATES PATENTS 2.582.020 l/l952 Friedman 222/48 X2.765.954 l0/l956 Wohlbier....... 222/48 X 3.2l6.630 ll/l965 Stull222/52l X 3.407.967 Ill/i968 Stull 222/52] X Primary Examiner-Samuel F.Coleman Assistant Examiner-Larry Martin Atramey -H. Gibner LehmannABSTRACT: A dispensing and metering cap construction comprising athreaded tubular spoutlike cap body and an orilice-type screw cap bothof molded plastic composition. In ad dition to the screw threads on thecap and cap body. the cap has a stop lug which is especially arranged toconstitute a cam follower whereby it also serves somewhat like a threadelement adapted to engage a cam track at the base of the cap body. Boththe screw threads and the cam track and follower lug serve to raise thecap on the cap body in response to unscrewing movement. The extent ofunscrewing determines the size of the opening of the discharge orificein the cap. The cam track constitutes a positive or nonyielding leadmeans for the cap. whereas the screw threads are yieldable andimpositive. Thus the cam track is the dominating one of the two leadmeans. By providing a hump or depression in the cam track, an accurateraised axial position of the cap can be readily effected for a givenrotative position, without requiring an accurate corresponding relativepositioning of the screw threads. since the latter can be made to yielda lesser or a greater amount under the influence of the cam track. Theprovision of the hump or depression thus can be used to attain anaccurate metering position of the cap. and is easier to accomplish thanaccurate reorientation of the screw threads.

CAI'I'IVE DISPENSING AND METERING CAP CROSS-REFERENCES TO RELATEDAPPLICATIONS AND PATENTS U.S. Pats. No. 3,216,630, No. 3,3l9,843, No.3,339,773, No. 3,35 l ,249 No. 3,407,967, No. 3,406,880, No. 3,370,764;Copending application of morton B. Stull, Ser. No. 855,971, filed Sept.8, I969 entitled Captive Dispensing Cap Construction, and having commonownership with the present application; and copending application ofMorton B. Stull, Ser. No. 867,l99, filed Oct. 17, 1969, entitled"Captive Cap for Dispensers, and having common ownership with thepresent application.

BACKGROUND This invention relates to dispensing type screw caps, andmore particularly to captive caps of this kind wherein the rotative capposition determines the orifice size and consequently the flow rate.

l-Ieretofore, flow measuring or metering screw caps wherein there is anorifice and a stopper plug movable in the orifice required a veryaccurate orientation of the screw threads with respect to the indicatormeans, in order to obtain any kind of meaningful reading of the flowrate for a given cap setting. Where liquids of difierent viscosity wereinvolved, the necessary shifting or alteration of this relativeorientation, involving mold changes and cut-and-try procedures, was timeconsuming and costly.

SUMMARY The above drawbacks of the prior dispensing closures of themetering type are obviated by the present invention, one subject ofwhich is to provide an improved dispensing and metering cap constructionwherein the orientation of the screw threads with respect to theindicator means need not be altered or changed from a given basicposition in order to effect the desired flow rate for a certain setting,or in order to make adjustment for difi'erent liquid viscosities. Thisis accom' plisbed by making the screw threads resilient and yieldable,and preferably of the buttress type, and by providing an easily alteredcam means or track operating concurrently with the screw threads toraise or position the cap and normally dominating the threads due to theyielding nature of the latter. The cam track can be made to have a humpor a depression at the place corresponding to the cap setting whichindicates the required flow rate, this being much more easily effectedthan changing the screw thread orientation. Thus a considerable savingin time and money is possible, as well as a more accurate indication ofthe flow rate.

Other objects and features of the invention reside in the provision ofan improved captive screw cap as above set forth, which is especiallyeffective and reliable in its operation, simple in construction,involves few parts, and is inexpensive to produce.

Still another features and advantages will hereinafter appear. In thedrawings:

FIG. I is a side elevational view of the cap body part of theconstruction, with the screw cap part shown in axial section.

FIG. 2 is a top plan view of the body part.

FIG. 3 is a bottom plan view of the body part.

FIG. 4 is a side elevational view of the screw cap part of theconstruction.

FIG. 5 is a top plan view of the screw cap part.

FIG. 6 is an axial section of the screw cap part, taken on line 6-6 ofFIG. 5.

FIG. 7 is a side elevational view of the cap construction with a portionof the cap part broken away. This view illustrates the interference andcamming action between the stop lugs during assembly of the cap part tothe body part.

FIG. 8 is a fragmentary sectional view taken on the line 8-8 of FIG. 2.

FIG. 9 is a view like that of FIG. 8 but showing a modification of theinvention.

Considering first FIGS. I and 7, the improved dispensing capconstruction of the invention is seen to comprise a cap body partdesignated generally by the numeral l0, and a screw cap part designatedgenerally by the numeral I2. The cap body part is of tubularconfiguration, being adapted for attachment to a container (not shown)as by means of internal screw threads 14 disposed in a lower portion I6.It will be understood that the portion I6 of the body part may bescrewed onto the threaded neck of the container.

The body part 10 has a discharge spout portion I8 terminating at itsupper or outer end in a stopper pin 20 which is supported by three webs22 defining triangular openings 24 through which the product from thecontainer can pass after traversing the spout portion. The screw cappart 12 has a central opening 26 in its tip to accommodate the stopperpin 20 when the cap is screwed down to its full-on position as shown inFIG. I. A seal is thus effected by the pin 20, preventing leakage of theproduct from the cap construction. The screw cap part 12 also hasannular sealing surfaces 28, 29 arranged for tight engagement with ashoulder portion 30, 31 of the spout I8 to effect a seal below thetriangular openings 24 of the spout.

The body part [0 and screw cap part 12 have a pair of mutuallyengageable portions comprising cooperable screw thread means 32, 34respectively on said parts for moving the cap part axially as it isturned. The screw thread means comprises a helical thread element 32which are preferably of the buttress type, said thread element havingworking surfaces characterized by a relatively small slope or angle withrespect to the axis of the cap construction. The arrangement is suchthat, as in the present case where there is a certain degree ofyieldability of the parts, the thread elements may be stripped past eachother by applying an excessive axial force to the cap part 12 in adirection tending to remove the same. However, the nonsloping shouldersof the buttress thread element prevent an opposite stripping, that is,prevent the cap part from being forcibly applied to the body part bypurely axial movement.

In accordance with the present invention at least one of the parts ofthe cap construction, and preferably both said parts are constituted ofresilient, yieldable plastic substance such as polyethylene or othersuitable wellknown formulation whereby advantage is taken of theyieldability to facilitate the obtaining of the proper flow rate for agiven dispensing setting of the cap part I2. As in my referred tocopending applications, the cap part is normally held captive on thebody part after it has been screwed on the latter to the full-onposition or at least past an intermediate position representing thefullopen or unstopped condition of the cap.

The helical thread elements 32, 34 function to effect upward anddownward (as viewed in FIGS. l and 7) axial movement of the cap part 12as the latter is turned in counterclockwise and clockwise directions (asviewed from the top). If, when the cap part I2 is first applied to thebody part It) and screwed down, it should encountered some momentaryobstruction to its axial movement as later described, one or both of thethread elements 32. 34 can yield as the cap part is momentarily haltedaxially. One thread element will tend to ride up on the other. and whenthe obstruction to axial movement of the cap part ceases, the threadelements will tend to spring the cap part I2 downward or toward itsfull-on position as the elements restore to their initial, normal ornonyielding nondeformed condition.

In accordance with the present invention the body part III has aspecially constituted second or additional thread element whichdominates the threads 32. 34, said second element comprising a helicallyfaced cam track 36 provided around the base of the spout portion II,which cooperates with an interior lug 38 provided within the bottom rim40 of the cap part 12. The lug 38 rides on the cam track 36 and impartsa positive or nonyielding outward axial movement to the cap part as thelatter is turned in unscrewing direction. The metering function of thelug 38 as it is involved with the present invention, is describedfurther below.

As in my copending applications, the cap and body parts have a secondpair of mutually engageable portions, comprising cooperable stop lugsone of which is constituted as the lug 38. The second lug, disposed onthe spout portion 18 of the body part, is designated 42 and is disposedat the high end of the cam track 36. The stop lug 42 has oppositesurfaces 44, 46 which are respectively engageable with opposite surfaces48,50 of the stop lug 38. Also, the surface 46 the lug 42 has a cammingportion 52 constituting a face which slopes with respect to thedirection of movement of the lug 38 of the cap part 12. The cam surface52 is adapted to be engaged by the stop lug 38 of the cap part 12 as thelatter is screwed onto the body part 10, such engagement beingillustrated in FIG. 7. The engagement with the sloping face 52constitutes a momentary obstruction or impediment, as above mentioned,to the downward axial movement of the cap part I12 and in fact causes anopposite or slightly raising movement of the cap part as the turning ofthe latter is continued. During such reverse movement, the threadelements 32, 34 will yield, one element riding up an extent on the otheras permitted by the slightly sloping engaged faces of the elements.Referring again to FIG. 7, as the clockwise turning movement of the cappart 12 is continued, the stop lug 38 thereof will be forced past thetop of the lug 42 of the body part It) and upon reaching the surface 44of the lug 42 it will snap downward so as to engage the high portion ofthe cam track 36. This snapping downward of the lug 38 and cap part [2is due in part to the tendency for the deformed thread element to resumethe nonyielding or unsprung condition. Also, the equipment (not shown)which applies the screw cap 12 may have a spring action by which the cappart is yieldably urged downward as it is being screwed onto the bodypart 10.

Upon the lug 38 of the cap part being cammed past the lug 42 of the bodypart, the screwing-on movement of the cap part can be continued until itreaches the full-on position of FIG. I.

Thus, as the consumer unscrews the cap part 12 to avail himself of theproduct, the lug 38 can be brought into engagement with the stop surface44 of the lug 42, whereby further unscrewing of the cap part 12 will beprevented. For the fullon position of the cap part, the surface 48 ofthe lug 38 is engaged with the surface 46 of the lug 42, whereupon thereexists positive stops defining not only the full-on position of thescrew cap but also the full-open position of the same.

For different intermediate positions of the cap part l2, the extent ofclosing of the discharge opening 26 by the sealing pin is varied, thusproviding a degree of control of flow of the liquid productfrom thecontainer. This variation of the size of *the opening 26 is detenninednot only by the screw threads 32,

34 but also by the cam track 36 and the cam follower lug 382' As alreadymentioned, the cam track and follower lug dominate the raising movementof the cap part 12, since the screw threads 32, 34 are yieldable.Preferably the relative orientation of the screw threads and cam trackis such that the screw threads are always slightly distorted orcompressed whereby they cause the cap part l2 to continuously exert adownward pressure on the track through the medium of the follower lug38. In consequence, the configuration of the cam track will be the mainfactor in determining the axial position of the cap part 12 and theextent of opening of the orifice 26 for any rotative position of the cappart.

The cap construction includes an indicator means, comprising an indexgroove 56 in the outside surface of the cap part 12, and cooperableraised portions or ribs provided in the top shoulder portion of the bodypart 10. As seen in FIG. 2, there is shown a single raised portion orrib 58 for indicating the closed position of the screw cap, a pair ofribs 60 for indicating a partially open or slow dispensing position ofthe screw cap, a set of three ribs 62 for indicating a more fully openposition of the screw cap part, and a set of four ribs 64 to indicatethe fully opened position of the screw cap. That is, when the groove 56of the cap part 12 is opposite the ribs 64, the cap will be fullyopened, whereas when the groove 56 is opposite the two ribs 60, thescrew cap will be only partially opened.

In accordance with the present invention, the cam track 36 is somodified that, for a given dispensing position of the screw cap part 12the rate of flow or extent of opening of the orifice 26 may beaccurately correlated to the rotative setting of the cap part. Referringto FIGS. 2 and 8, for the dispensing setting where the groove 56 isopposite the ribs 60, the cam track 36 is provided with a hump 66 whichnormally causes the cap part 12 to be raised more than it would be ifthe track had no hump. The additional raising of the cap part is madepossible since the screw threads 32, 34 can yield the extent necessaryto permit the follower lug 38 to ride up on the hump 66. In reworkingthe molds for the body part 10, the alteration of the mold partnecessary to provide various sizes of humps 66 can be easily effected,much more so than if the adjustment of orifice size were to be attemptedby changing the orientation of one of the screw threads 32, 34. In likemanner, the cam track 360 illustrated in FIG. 9 may be provided with aslight depression 68 instead of the hump 66. In either circumstance, thealteration of the cam track, which dominates the raising movement of thecap part 12 as against the action of the screw threads 32, 34 can bemore easily effected and with greater certainty of arriving at therequired flow for a given rotative setting of the cap part at the ribs60, than if the adjustment had to be effected by a change in theorientation of the screw threads 32, 34.

The adjusting of the size of the orifice 26 and rate of flow to a givensetting of the cap part involves a somewhat cut-and-try procedurewherein trials are made with the liquid product, which has a certainviscosity. Accordingly, several alterations of the mold part to providedifferent configurations of the cam track may be necessary. Thecut-and-try procedures can be greatly shortened, however, byexperimentally placing wedges between the bottom rim 40 of the cap partI2 and the top shoulder surface of the body part II]. By adjusting theheight of the cap part I2 in this experimental manner while measuringrates of flow, the desired axial position of the cap part can be readilydetermined. It is then merely a simple matter to either add to ordetract from the height of the cam track 36 at the location of the lug38, by an amount equal to that experimentally found necessary to obtainthe desired rate of flow. Thus, it is seen that the alteration of thecam track can be effected much more quickly and accurately than areorientation of the spiral thread elements 32, 34 wherein there isinvolved a rotative positioning of the elements one with respect to theother.

It will now be understood from the foregoing that I have provided anovel and improved captive dispensing cap construction wherein the cappart is held from complete removal by a positive stop and has anintermediate dispensing position determined by an alteration in the camtrack 36 to enable the orifice size to be accurately related to the flowindicator means. The hump or the depression in the cam track is easilyeffected by simple mold changes, making the more costly andtime-consuming reorientation of the screw threads unnecessary. Theunscrewed or dispensing position of the cap part 12 and also the full-onor sealing position of the part are determined by positive action stoplugs, and the cap part is held captive on the body part once it has beenapplied thereto and screwed past the full-open dispensing position.

Variations of the structure shown are possible without departing fromthe spirit of the invention.

lclaim:

1. A captive dispensing cap construction comprising, in combination:

a. a tubular body part adapted to be carried by a container and having adischarge spout,

b. a screw cap part carried by said body part and surrounding saiddischarge spout,

c. said cap and body parts having two pairs of mutually engageableportions,

d. one pair of mutually engageable portions comprising said cam trackhaving a helical face on which the lug rides. and having an interruptionin said face at one point thereof whereby the cap part departs from itsuniform axial movement as the follower lug traverses said point duringturning of the cap part, and

indicator means on the body and cap parts, for indicating differentrotative positions of the latter.

. A cap construction as in claim I wherein:

the interruption in the cam track face comprises a hump thereon.

3. A cap construction as in claim I, wherein:

a. The interruption in the cam track face comprise a depression therein.

4. A cap construction as in claim I, wherein:

a. the cam track is on the cap body part.

5. A cap construction as in claim I, wherein:

a. the screw thread means comprises buttress thread elements arranged topermit the cap part to be stripped off the body part under the influenceof excessive axial force.

6. A cap construction as in claim I wherein:

a. the screw thread means comprises a helical thread element having arelatively small slope with respect to the axis of the cap construction.

7. A cap construction as in claim I, wherein:

a. The resilient screw thread means continuously tends to shift the cappart axially toward its full-on position.

1. A captive dispensing cap construction comprising, in combination: a.a tubular body part adapted to be carried by a container and having adischarge spout, b. a screw cap part carried by said body part andsurrounding said discharge spout, c. said cap and body parts having twopairs of mutually engageable portions, d. one pair of mutuallyengageable portions comprising cooperable resilient and yieldable screwthread means on said parts, for moving the cap part axially on the bodypart as the cap part is turned, e. the other pair of mutually engageableportions comprising a helical cam track and a follower lug respectivelyon the body and cap parts for moving the cap part axially as it isturned, substantially in a like manner to the unscrewing action of saidscrew thread means, f. said cam track having a helical face on which thelug rides, and having an interruption in said face at one point thereofwhereby the cap part departs from its uniform axial movement as thefollower lug traverses said point during turning of the cap part, and g.indicator means on the body and cap parts, for indicating differentrotative positions of the latter.
 2. A cap construction as in claim 1,wherein: a. the interruption in the cam track face comprises a humpthereon.
 3. A cap construction as in claim 1, wherein: a. Theinterruption in the cam track face comprise a depression therein.
 4. Acap construction as in claim 1, wherein: a. the cam track is on the capbody part.
 5. A cap construction as in claim 1, wherein: a. the screwthread means comprises buttress thread elements arranged to permit thecap part to be stripped off the body part under the influence ofexcessive axial force.
 6. A cap construction as in claim 1, wherein: a.the screw thread means comprises a helical thread element having arelatively small slope with respect to the axis of the cap constrUction.7. A cap construction as in claim 1, wherein: a. The resilient screwthread means continuously tends to shift the cap part axially toward itsfull-on position.